Russia's Karen Khachanov reached his first Grand Slam semi-final at the US Open on Tuesday with a 7-5, 4-6, 7-5, 6-7 (3/7), 6-4 win over Australian firebrand Nick Kyrgios.
Khachanov, seeded 27, fired 30 aces and a total of 63 winners past Wimbledon runner-up Kyrgios in a big-serving contest.
The 26-year-old will face fifth seed Casper Ruud of Norway for a place in Sunday's final.
"I did it, guys. Finally, you are showing me some love," Khachanov told the mostly pro-Kyrgios crowd on Arthur Ashe Stadium.
"It was a crazy match I was expecting it would be like this. I'm ready to run, to fight to play five sets. We played almost four hours and that's the only way to beat Nick," AFP quoted him as saying.
The Russian said he had "nothing to lose" when he faces French Open runner-up Ruud on Friday.
"I would like to win it," he said.
"But as deep as you go the expectations rise up. I did the step forward, I made my first semi-final and I think I have nothing to lose.
"I just want to go for it and be ready for the next match and hopefully it will be a good one."
Kyrgios was feeling his left knee at each changeover in the first set on Tuesday and summoned the trainer after dropping the opener complaining 'I can't walk'.
It was a rapid-fire first set dominated by serve with Khachanov sending down four successive aces to lead 6-5 before pouncing on the only break point to seal the set.
Despite his physical worries, the 27-year-old Kyrgios, who knocked out defending champion Daniil Medvedev in the fourth round, broke for 2-1 on his way to pocketing the second set.
Kyrgios served up a 47-second service game, courtesy of four aces in a row, but wasted two break points in the ninth game of the third set.
He was soon made to pay as the Russian edged ahead two sets to one.
Kyrgios was handed a code violation for unsportsmanlike conduct as he angrily berated himself at the changeover.
That will likely lead to another cash penalty to add to the $18,500 in fines he carried into Tuesday's tie.
Kyrgios broke for a 3-2 lead in the fourth but handed the advantage straight back with a lazy double fault.
Another opportunity went begging in the ninth game.
However, Kyrgios settled and as the clock ticked past midnight, he played an impressive tiebreak to send the quarter-final into a decider.
Khachanov broke for 1-0 in the final set while Kyrgios failed to convert break points in the second and fourth games.
The Russian went to match point off a net cord and claimed victory off an unreturned serve after three hours and 39 minutes of action.
Kyrgios hit 31 aces in his 75 winners but his unforced error count of 58 was almost double the 31 of Khachanov.
Earlier Tuesday, Ruud defeated Italy's Matteo Berrettini 6-1, 6-4, 7-6 (7/4) to make his second Slam semi-final of 2022.
